[R] aggregate function with 'NA'

[Peter Dalgaard]

Frank <rggefrm at ucl.ac.uk> writes:

>   aggregate(frame[,c(-1)],list(frame$Day,frame$Time),mean)
> 
> My problem is now that I do not obtain a 'mean' for Day=M/Time=0 and 
> Day=M/Time=1,
> 
> because aggregate ignores all values for a grouping variable if NA 
> occurs.

No. But mean() will give an NA result if any vaues are NA.
 
> I'm now hoping for some help so that the mean is still calculated in 
> this group.

add na.rm=TRUE

-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
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